| 摘要 |
PURPOSE:To prevent the leakage of a diagnosing signal to a receiver during a reception by intersupting a connection between a receiver input terminal and a high frequency amplifier system circuit at the self-diagnosing state so as to eliminate the effect of a cable wired from a receiver switch up to receiver input terminal. CONSTITUTION:In giving a self-diagnosing control signal to the self-diagnosing control signal input terminal 2 of a standby receiver 21 in the reception standby state, the switching circuit 3 of the standby receiver 21 is opened. The self- diagnosing control signal is inputted to a supervisory noise generating circuit 5, where a diagnosing signal is generated, but the switching circuit 3 is closed, then all the diagnosing signals are inputted to a high frequency amplifier circuit 6 via a coupling circuit 4. Thus, the self-diagnosing signal is not leaked to other receiver during the reception in the receiving operation via a receiver switch 19 and the effect of the coaxial cable from the switch 19 up to the receiver input terminal 1, then the diagnosing signal level from the supervisory noise generating circuit 6 is set lower. |
